Blue-fluorescent and biocompatible carbon dots derived from abundant low-quality coals.

Coal is one of the most abundant natural carbonaceous materials. This paper reports a novel oxidative chemical method for the synthesis of high-value carbon dots (CDs) from cheap and abundant low-quality high‑sulfur coals for use in high-end applications. These CDs were synthesized by using wet-chemical ultrasonic stimulation-induced process which is environmentally facile and less drastic compared to other chemical methods of production of CDs.